So, if you copy paste a bunch of tags separated by comma, they do not become tags instantly. This behavior has changed since Beta 5. If this is intentional, it's alright. But it does have a few annoyances. Box resizes when tags are converted and it resizes again when dupes are cleaned up. Basically, you cannot just click on the save button in case like the screenshot above. It would resize twice and you would miss the save button both the times.
I do see why the change might have been made. On Beta 5 (and earlier builds), copying a phrase or word in tag editor would...